Crosman .177-Cal Steel Breech Kit, Fits 1377, 1740, 1760 & PC77 Air Guns

Everything.

I would make this the factory installed breech and never, ever subject another customer to the worthless plastic breech that is the current standard.

It is worth the upgrade.

Great product, but I do it consider this an upgrade it's more of a retro part in order to utilize optics. The plastic breech is good and has no problems loading pellets. But with the steel breech a washer must be used to raise the breech screw in order to eliminate the pellets from jamming. The paper washer is the way I fixed the pellet jamming problem. Also the paper washer cost nothing, just take your time and cut some hard paper and problem solved.

I would add some paper washers in the breech kit.

Pellet jam occurs with this retro/upgrade.

This gives you the ability to mount optics on your 1377. It improves and already accurate pistol. I think it makes pumping the gun easier as it stiffens the overall barrel breech connection. The pistol feels a lot more robust.

The biggest issue with this kit is that breech screw hole. The pellet will hang up and requires a lot of work to load properly. Crosman has know about this issue forever and just cannot seem to figure out how to include a simple nylon washer/spacers (like 3 cents guys- come on!) I was frustrated that they cannot include a slightly longer rear mount screw so the original sight can be utilized. (ok another 3 cents- but I would have GLADLY paid an extra quarter for those parts!) The barrel grub screw is WAY too long for the 1377 application and my dovetail to Weaver adapter had to be mounted in a way to accommodate the grub screw sticking up (I am going to find a shorter one in my screw collection and replace it. Crosman put lock tight on every screw EXCEPT the bolt handle threads (the one screw that actually NEEDS locktite)

This takes your 1377 from a cheap beginner pistol, to a serious contender. Yes it is expensive (taking the price of the gun to the $100 dollar range) but it makes a difference in what can be done. Be aware the directions are for the 22xx/23xx series and not really user friendly for the 13xx series. My transfer hort fell out and I had a Heck if a time figuring out which end went up (it only fits properly one way). You cannot reuse the stock sight as the included (and original screw are too short. The barrel band on the new version of the 1377 does not need to be loosened (it can't be loosened) and you need to remove the lower tube hammerspring retaining plug (and the spring will fall out). This is challenging to replace as you need to compress the spring and line up the cap holes AND start the screw! I'm not a beginner when it comes to airguns, but this took me about 45 minutes to complete (from removing the old breech to a completed project.